Toyota AT180 Series Repair Manual page 188

* AUTO FUNCTION
WHEN THE AUTO SW (A/C CONTROL ASSEMBLY) IS TURNED ON, SIGNALS ARE INPUT TO TERMINAL BSW OF A/C AUTO AMPLIFIER
AND TERMINAL B AUTO OF A/C AUTO AMPLIFIER CONTROLLING THE CURRENT FLOW FROM TERMINAL BLW OF THE A/C AUTO
AMPLIFIER TO TERMINAL 3 OF POWER TRANSISTOR
BLOWER MOTOR STEPLESSY.
3. OPERATION OF RECIRC/FRESH CONTROL SERVO MOTOR
(SWITCHING FROM FRESH TO RECIRC)
WITH IGNITION SW TURNED ON, THE CURRENT FLOWS FROM GAUGE FUSE TO TERMINAL 1 OF RECIRC/FRESH CONTROL SERVO
MOTOR. WHEN THE RECIRC/FRESH SW IS SWITCHED TO THE RECIRC SIDE, TO CURRENT FLOWS FROM TERMINAL 1 OF
RECIRC/FRESH CONTROL SERVO MOTOR
TERMINAL A2 GROUND, THE MOTOR ROTATES AND THE DAMPER MOVES TO THE RECIRC SIDE.
WHEN IT IS IN THE RECIRC POSITION, THE CURRENT IS CUT INSIDE THE SERVO MOTOR AND THE DAMPER STOPS AT THAT
POSITION.
(SWITCHING FROM RECIRC TO FRESH)
WITH IGNITION SW ON, WHEN THE RECIRC/FRESH SW IS SWITCHED TO THE FRESH SIDE, THE CURRENT FLOWS FROM TERMINAL
1 OF RECIRC/FRESH CONTROL SERVO MOTOR
GROUND, THE MOTOR ROTATES AND THE DAMPER MOVES TO THE FRESH SIDE. WHEN IT IS IN THE FRESH POSITION, THE
CURRENT IS CUT INSIDE THE SERVO MOTOR AND THE DAMPER STOPS AT THAT POSITION.
4. OPERATION OF AIR VENT MODE CONTROL SERVO MOTOR
WITH IGNITION SW TURNED ON, THE CURRENT FLOWS FROM GAUGE FUSE TO TERMINAL 5 OF AIR VENT MODE CONTROL SERVO
MOTOR TERMINAL 6 GROUND, AND THE DAMPER MOVES TO THE POSITION OF THE MODE SELECTION SW OF THE CONTROL
ASSEMBLY SWITCH IS ON.
WHEN THE MODE SELECTION SW OF A/C CONTROL ASSEMBLY IS MOVED TO DEF POSITION FROM THE DAMPER IN THE FACE
POSITION, THE CURRENT FLOWS FROM TERMINAL 7 OF AIR VENT MODE CONTROL SERVO MOTOR TO TERMINAL A13 OF A/C
CONTROL ASSEMBLY TERMINAL C2
AS A RESULT, TO SERVO MOTOR OPERATES UNTIL THE DAMPER REACHES DEF POSITION.
WHEN THIS OCCURS THE CURRENT TO THE A/C CONTROL ASSEMBLY IS SHUT OFF AND ROTATION OF THE MOTOR STOPS.
SWITCHING TO OTHER MODES IS CONTROLLED BY THE SERVO MOTOR ACCORDING THE FLOWING CURRENT:
1. FOOT/DEF POSITION: THE CURRENT FLOWS FROM TERMINAL 4 OF SERVO MOTOR TO TERMINAL A12 OF A/C CONTROL
ASSEMBLY.
2. FOOT POSITION: THE CURRENT FLOWS FROM TERMINAL 3 OF SERVO MOTOR TO TERMINAL A11 OF A/C CONTROL
ASSEMBLY.
3. BI–LEVEL POSITION: THE CURRENT FLOWS FROM TERMINAL 2 OF SERVO MOTOR TO TERMINAL A10 OF A/C CONTROL
ASSEMBLY.
5. OPERATION OF AIR MIX CONTROL SERVO MOTOR
WHEN THE TEMPERATURE CONTROL VOLUME IS TURNED TO THE COOL SIDE, A SIGNAL IS INPUT TO TERMINAL TEST OF A/C
AUTO AMPLIFIER FROM TERMINAL C1 OF A/C CONTROL ASSEMBLY.
AS A RESULT, THE CURRENT FLOWS FROM TERMINAL MH OF A/C AUTO AMPLIFIER TO TERMINAL 2 OF AIR MIX CONTROL SERVO
MOTOR TERMINAL 6 TERMINAL MC OF A/C AUTO AMPLIFIER
SERVO MOTOR TO ROTATE.
AT THIS TIME IS INPUT THE DAMPER OPENING ANGLE FROM TERMINAL 4 OF SERVO MOTOR TO TERMINAL TP OF A/C AUTO
AMPLIFIER THIS IS USED TO DETERMINE THE DAMPER STOP POSITION AND MAINTAIN THE SET TEMPERATURE.
WHEN THE TEMPERATURE CONTROL VOLUME IS TURNED TO THE WARM SIDE, IN A/C SYSTEM AMPLIFIER THE CURRENT FLOWS
FROM SERVO MOTOR TERMINAL MC OF A/C AUTO AMPLIFIER
TERMINAL 2 TERMINAL MH OF A/C AUTO AMPLIFIER
SWITCHING THE DAMPER FROM COOL TO WARM SIDE.
TERMINAL 2
TERMINAL 2 TERMINAL A18 OF RECIRC/FRESH CONTROL SERVO MOTOR
TERMINAL 3 TERMINAL A8 OF A/C CONTROL ASSEMBLY
GROUND.
TERMINAL GND
TERMINAL 6 OF AIR MIX CONTROL SERVO MOTOR
TERMINAL GND
GROUND, THE A/C AUTO AMPLIFIER CONTROLS THE
GROUND. CAUSING THE AIR MIX CONTROL
GROUND, ROTATING THE MOTOR IN REVERSE AND
TERMINAL A2
MOTOR
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